1. Field of the Invention
The present invention pertains to arrangements for sorting pigs by weight and holding for market shipment, and more particularly to pen and feeding configurations in “wean to finish”, or “finisher”, facilities.
2. Preliminary Discussion
In the present practice of raising hogs for commercial use, such hogs are typically housed in large buildings or adjacent buildings comprised of several containment rooms, each of which is divided into a plurality of small rectangular pens per room, with each pen holding 15 to 50 and preferably 25 to 35animals and having one gate per pen. While the basic concept of dividing a finishing building or barn into a number of separate pens has been standard practice for decades, the disadvantages of such a pen design or layout are numerous. For example, it is well known that confining hogs in small, overcrowded pens leads to stress and agitation and fighting amongst the animals, as well as contamination from wastes. In addition, each pen usually has its own feeder and waterer, so that caretakers must check each individual pen for an adequate supply of feed and water as well as good health of the hogs, which is very labor intensive and time consuming.
Another drawback of the traditional system is the time spent in sorting the hogs. At market time, each pen must be checked for hogs that meet market weight. This is usually done by chasing whole pens of hogs down an alleyway and forcing them across a scale. The hogs are then hand-separated, with heavier pigs entering the market truck, and lighter pigs being herded back to their respective pens. This method of sorting hogs by weight is very time-consuming, and furthermore poses a risk of injury to both humans and animals. Another type of sorter wherein hogs are sorted by size rather than weight is shown in U.S. Pat. No. 3,072,100 issued to H. E. Dustin, entitled “Animal Sorter,” wherein the sorter is comprised of an adjustable gate sized so that smaller hogs can fit through the bars in the gate, while larger animals ready for market cannot.
An alternative method of sorting hogs by weight that is sometimes utilized in sorting hogs confined in small pens involves estimating weights by sight. However, estimating weights produces very inaccurate results, which mistakes can be very costly, since at the marketplace sort bonuses are typically awarded for hogs that fall within a specified weight range. Hogs that are not in this range do not receive a bonus, and in fact may be docked in price. Therefore, while it is more desirable to use a scale rather estimating weights manually, use of a scale is more costly and time consuming.
In addition, it is desirable to ship hogs with empty stomachs. Feed in the stomach can be worth up to 50 cents per pound, which cumulatively represents a significant expenditure, particularly for larger finishing facilities. In addition, if the hogs are shipped with full stomachs, a feed disposal problem at the packing plant results. It has also been found that if the hogs are held off feed for 24 hours before packing, the meat has a lower pH and as a result has a better taste. The only way to achieve empty-stomach shipment is to hold market hogs off of feed for 24 hours, which is impossible in a standard system because market weight and light weight animals are mixed throughout each pen. It is also often desirable to water hogs with electrolytes prior to shipping in order to help the animals to retain water and reduce water shrinkage. However, this is also impossible in the current practice of raising hogs because it is not cost-effective to feed watered electrolytes to an entire room or pen of market weight, as well as non-market weight, hogs.
Hogs are generally social animals, but, as indicated above, confinement in small pens can lead to stress and agitation. Over time, closely confined hogs become weaker and less healthy. This in turn can effect their eating habits and growth rate. Thus, it has been found that if the hogs are allowed to roam and mingle in a larger environment and are not confined to a small pen, they will be less agitated and kept in a calmer state. In addition, there will be less of a pecking order which inevitably develops in each small pen, since in a larger pen the dominant hogs will not be able to fight every other hog, which inability leads to fewer overall fights and consequent injuries. Sorting hogs by weight using an electronic scale is also easier in a large pen environment, since the hogs can be separated into different areas of the pen after sorting depending upon their weight. Still, the provision of an electronic sorting scale in each pen is costly, as the cost of such scales can usually range between five to ten thousand dollars or more. Since the profit margins of hog finishing buildings is usually quite low, the expense of providing a scale in each pen can make the entire operation cost prohibitive.
3. Description of Related Art
Numerous methods and arrangements for managing or sorting animals by size, weight or other criteria are available in the prior art. The following prior art patents related to sorting or separating of livestock or the like incorporating concepts bearing upon the present invention are known by the present inventor. None of such references, however, discloses a hog sorting gate and fencing system and method in a large pen building environment wherein a single stationary electronic sorting scale can be used to sort hogs in adjacent large pens as conceived by the present inventor. Neither do any of such references disclose the novel sorting methods and arrangements of the present invention whereby superior and effective management of hog finishing operations is obtained.
One common sorting method is to herd animals through a gate wherein upon exiting the gate they can be individually directed to different pens or holding areas. For example, U.S. Pat. No. 182,688 issued to A. Minor, entitled “Stock Separator,” discloses an early gate system for separating livestock wherein two pivotable panels positioned near an entranceway funnel the livestock through a gate one at a time, and wherein a third panel positioned outside the exitway is manually swung from side to side depending on which direction it is desired to push the livestock.
Other arrangements wherein animals are guided through chutes into a desired holding area are also known. U.S. Pat. No. 2,050,527 issued to C. Grabe, entitled “Animal Chute,” discloses a chute formed by a pair of parallel stationary fences having two swinging or alternatively positionable fence sections therebetween, so that the fence sections can be manipulated and positioned to channel livestock in a particular direction such as into a certain pen or corral. U.S. Pat. No. 3,545,407 issued to W. T. Moore, entitled “Animal Pen,” discloses a pen comprised of a plurality of pivotable outer fence sections surrounding a chute-like passageway, wherein the outer sections can be positioned to direct a herd of animals as desired.
U.S. Pat. No. 4,136,641 issued to H. F. Hoffman, entitled “Livestock Sorting Gate,” discloses a three-sided swinging gate pivotally connected in series so that it swings as a unit from side to side, thereby either opening or closing off entrances to opposing pens. U.S. Pat. No. 4,261,297 issued to E. Van Maarion et al., entitled “Animal Processing System and Cutting Gate,” discloses another generally triangular swinging gate which can be situated so as to allow entry into or block entrance into various fenced areas. Van Maarion et al. also utilizes simple arcuate swinging gates in combination with the triangular gate to increase the effectiveness and versatility of the triangular gate. U.S. Pat. No. 4,552,096 issued to W. J. Forrest on Nov. 12, 1985, entitled “Sorting Gate Assembly,” discloses a pivotable gate for use in a holding pen, which gate can be moved to various positions to corral or sort the animals. While such gates are used to urge or force animals in a particular direction or into a particular pen, the animals are separated by visual inspection rather than by weighing.
Another common sorting arrangement is to provide a doorway or opening through which only animals below a predetermined size can fit. One such arrangement is illustrated in U.S. Pat. No. 1,381,797 issued to H. D. Caspers, entitled “Stock Separator,” wherein the distance between a pair of vertical rollers is adjustable so that only hogs smaller than a selected size can fit through such opening. Another example is U.S. Pat. No. 1,788,244 issued to J. E. Larson, entitled “Stock Separator,” which discloses a feed house having openings doors adjustable so that while smaller pigs can pass through the doors, larger pigs cannot and therefore eat less. As indicated above, U.S. Pat. No. 3,072,100 issued to H. E. Dustin, entitled “Animal Sorter,” discloses a sorter for selecting and segregating hogs which are ready for market, comprising an adjustable gate wherein smaller hogs can fit through the bars in the gate, while larger animals cannot. Other similar arrangements can be found in U.S. Pat. No. 3,861,359 issued to R. Pals, entitled “Hog Sorter Gate Device,” U.S. Pat. No. 3,894,516 issued to M. J. Schaefer, entitled “Animal Sorting Gate,” U.S. Pat. No. 4,019,464 issued to T. G. Miller, entitled “Animal Size Sorting and Control Gate” and U.S. Pat. No. 4,572,109 issued to E. T. Nixon, entitled “Animal Separator Gate.” While over time such sorter gates divide the animals into groups of larger and smaller size, none of such gate systems represents a significant improvement over merely visually estimating the size of the animals. Such systems simply cannot segregate animals with sufficient accuracy for the packer to receive sort bonuses for meeting packer weight specifications.
Various gates or chutes for sorting animals by weight are also known. U.S. Pat. No. 4,134,366 issued to J. L. Elliot, entitled “Animal Sorter,” discloses a sorter wherein the end of a chute is aligned with either a first or second exit depending upon the weight of the animal. If the weight of the animal exceeds the weight of a counterweight, the first exit is opened, while if the weight of the animal is less than the counterweight, the second exit is opened. U.S. Pat. No. 4,138,968 issued to J. L. Ostermann, entitled “Automatic Sorting Device for Livestock,” discloses a chute also having a weighing means therein such that the weight of the animal determines which of two passageways is opened.
In U.S. Pat. No. 4,280,448 issued to J. L. Ostermann, entitled “Livestock Sorting Device,” animals are individually weighed in a chute and then directed into one of two fenced areas. Ostermann shows a manual method for directing hogs to a particular pen based on weight. To use the sorter, an entrance gate is opened by the operator, allowing an individual hog to enter, with the exit blocked by a second gate. After the weight of the animal is determined, the second gate is opened and the hog is directed to one of the fenced areas by manually manipulating a gate operating arm. One of such areas is designed to hold sorted animals ready for market, while the other area is for animals not ready for market.
U.S. Pat. No. 4,162,682, issued to W. K. Miller, entitled “Pivotal Sectionalized Wall for Hog Raising Enclosure,” discloses a gate system for use in hog barns of the conventional type wherein hogs are housed in small individual pen areas, rather than in large open finishing barns or buildings. In Miller, sections of the walls of multiple pens can be moved for ventilation or the like using mechanical interconnection.
U.S. Pat. No. 5,878,695 issued to J. F. Gent, entitled “Extendible Hog Gate and Confinement Facility Gate System,” discloses a more recent hog pen forming gate, wherein each gate apparently has a stationary portion and a pivotable portion. Such gates allow the size of the pens and walkways between the pens to be varied depending on the space required or the number of hogs in a pen.
More recently, electronic identification or sorting systems have become increasingly common. U.S. Pat. No. 5,183,008 issued to J. A. Carrano, entitled “Livestock Sorting System Having Identification Sensor and Gate Mounted Exit Switch,” discloses a sorting system which uses a sensor to read electronic identification tags on livestock, which sensor then causes a gate to move to either a first or second position. Carrano uses electronic identification, rather than size, weight, or some other factor to sort the animals. U.S. Pat. No. 5,595,144 issued to U. Löher, entitled “Device for Sorting Animals,” discloses another sorter which utilizes electronic sensors to direct animals into a particular area. A first sensor in the passageway identifies the animal, and a second sensor positions the gate. The two sensors are spaced apart so that the device can quickly sense and respond to different animals to be sorted. U.S. Pat. No. 5,979,365 issued to K. Sorraghan et al., entitled “Animal Sorting Module,” discloses a passageway for sorting animals which employs cylindrical rollers at the entry and exit points of the passageway. Such rollers are preferably operated by a computer which reacts to sensors on the system to detect particular animals, and which close around the flank of the animal to prevent a following animal from entering the passageway at the same time. Sorraghan et al. presents a solution to the problem of more than one animal trying to squeeze into the passageway at the same time.
U.S. Pat. No. 5,579,719 issued to S. J. Hoff et al., entitled “Method and Means for Quasi Ad-Libitum Feeding for Gestation Sows in Loose Housing,” discloses an improved electronic identification and feeding system for gestating sows. Gestating sows are kept in a confined area having a separate feeding area. To enter the feeding area, hungry sows, wearing a computer scanable responder tag, pass through a one-way gate with a scale, wherein the tag number is read by the computer. Once the sow and her weight are identified, the computer determines which feed pen the sow should be directed to, and the gate to such feeding area is opened. If the feeding area is currently full, the sow will be passed back to a confined bedding area. The sorting systems which utilize an electronic sensor to identify individual animals are expensive, and are not usually necessary for sorting hogs that are ready for market from those that are still too light, although the present inventor may include an electronic sensor means to detect whether or not an animal is currently on the scale, and in addition none of such references includes a gate system similar to the present system.
U.S. Pat. No. 6,135,055 issued to W. C. Pratt on Oct. 24, 2000, entitled “Cattle Management System and Method,” discloses a state-of-the-art, high tech system for monitoring and keeping track of characteristics of each individual animal. As cattle are passed through a chute one at a time, vital statistics are recorded wherein a computer automatically directs the animal either to a shipping pen or a feeding pen. The Pratt system also keeps track of statistics up until and including the slaughter process.
Finally, at least one reference showing a finishing barn design wherein the hogs are held in a larger communal setting is also known. U.S. Pat. No. 4,442,792 issued to A. C. Nehring, entitled “Hog Finishing Building,” discloses a barn arrangement wherein the hogs are not confined to small pens but are allowed to move around and mingle. The feeding area is centrally located, and the floor is slatted to allow waste to fall between the floor boards. Nehring also shows several interior side and end walls, but does not include any hog segregating or weighing devices, or a pivotable fencing arrangement, and is not directed to weighing and sorting the hogs.
The inventor is also aware that a Canadian company, K&L Technical Services, Ltd., is manufacturing a sorting scale under the name the “Super Sorter.” Such sorter is placed in a common area between a pig barn and feeding area, so that the pigs can be made to pass through the sorter on the way to the feeding area. The sorter then weighs the pigs and directs pigs that have reached market weight to the shipping pen, while light pigs are directed to the feeding pen. While the above sorter is used in an open pig barn similar to the present system, it is not used in combination with a gate system wherein such barn is divided into two open pens wherein a single weighing and sorting scale can be utilized to weigh and sort hogs in both pens, as well as between pens.
Despite the significant advances in animal sorting and management systems known in the prior art, there is still a need for a more efficient finishing barn design wherein hogs are not held in small groups in a plurality of small pens, but rather are placed in large pens so that they can move around in a larger area, which reduces stress and keeps the hogs in a calmer state and enhances growth. In addition, such large pens may have a centralized feeder and accurate sorting system wherein the animals safely sort themselves by weight into groups ready for market and groups which are not. In addition, there is a need for a system wherein two large pens can utilize a central weighing, sorting and feeding area, and wherein the hogs can be sorted between pens in addition to within such pens, thereby decreasing labor, set-up, and maintenance costs of the system while enabling producers to better manage and monitor hog growth in such pens and increase profits.